Testis & paratestis

Germ cell tumors

Embryonal carcinoma

Editorial Board Member: Bonnie Choy, M.D.
Deputy Editor-in-Chief: Maria Tretiakova, M.D., Ph.D.
Anastasia Lendel, B.A.
Debra L. Zynger, M.D.

Last author update: 9 February 2022
Last staff update: 3 March 2022

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PubMed Search: Embryonal carcinoma [TI] testis pathology

Anastasia Lendel, B.A.
Debra L. Zynger, M.D.
Page views in 2023: 49,691
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Cite this page: Lendel A, Zynger DL. Embryonal carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisembryonal.html. Accessed May 19th, 2024.
Definition / general
  • Pluripotent and malignant germ cell tumor (GCT) resembling undifferentiated stem cells during embryonic development
Essential features
  • Pleomorphic, high grade appearing type of GCT
  • Usually occurs mixed in combination with other types of testicular GCT
  • Predominance in a mixed GCT is associated with a higher risk of metastases and relapse (BJU Int 2020;125:355, BMC Cancer 2020;20:728)
  • Positive: OCT 3/4, CD30; negative / weak: D2-40, CD117, glypican 3
ICD coding
  • ICD-O: 9070/3 - embryonal carcinoma, NOS
  • Testis
  • Anterior mediastinum
  • Retroperitoneum
Clinical features
  • Ultrasound
  • Serum tumor markers
  • CT imaging with contrast of chest, abdomen and pelvis to evaluate for metastasis
  • Radical inguinal orchiectomy with histopathologic evaluation is necessary for definitive diagnosis
  • Serum tumor markers should not be used as a screening tool
  • Elevated serum human chorionic gonadotropin (hCG), alpha fetoprotein (AFP) and lactate dehydrogenase (LDH) may be present (J Clin Oncol 2010;28:3388)
  • Current guidelines recommend measuring hCG, AFP and LDH before and after initial treatment (J Clin Oncol 2010;28:3388)
  • Serum tumor markers can be used to monitor for recurrence
Radiology description
  • Heterogenous and hypoechoic appearance on ultrasound; microlithiasis may be present (J Clin Ultrasound 2010;38:21)
  • Testicular non(pure)seminomatous GCTs appear heterogenous on MRI, with enhancement in areas of necrosis and hemorrhage (AJR Am J Roentgenol 2007;189:W331)
  • CT imaging is recommended to identify presence of metastases
  • Lymph node metastases from testicular nonseminomatous GCTs appear heterogenous or cystic on CT imaging (Radiol Clin North Am 2012;50:1111)
Radiology images

Images hosted on other servers:

Calcified mass

Prognostic factors
Case reports
  • Initial management is radical inguinal orchiectomy
  • No further treatment necessary in 75% of clinical stage I nonseminomatous GCT (Ann Oncol 2010;21:1296)
  • If pT2 or higher, retroperitoneal lymph node dissection or chemotherapy
  • If pN2 - 3, chemotherapy
  • Resistant to radiation therapy (Arch Pathol Lab Med 2012;136:435)
Clinical images

Images hosted on other servers:

Cryptorchid testis with embryonal carcinoma

Gross description
  • Gray-tan mass with hemorrhage and necrosis
Gross images

Contributed by Debra L. Zynger, M.D.

Mixed GCT with predominance of embryonal carcinoma

Mixed GCT with minor component of embryonal carcinoma

Microscopic (histologic) description
  • Multiple growth patterns usually present (Am J Surg Pathol 2014;38:689)
  • 3 most common growth patterns: solid (55%), glandular (17%) and papillary (11%) (Am J Surg Pathol 2014;38:689)
  • Rare patterns: nested (3%), micropapillary (2%), anastomosing glandular (1%), sieve-like glandular (< 1%), pseudopapillary (< 1%), and blastocyst-like (< 1%) (Am J Surg Pathol 2014;38:689)
  • Polygonal cells (Arch Pathol Lab Med 2007;131:1267)
  • Cells are crowded, have indistinct distinct cell borders and appear to have overlapping nuclei
  • Moderate amount of amphophilic and granular cytoplasm
  • Pleomorphic, high grade nuclear features
  • Mitotic figures are common
  • Smudgy degenerative appearing nuclei are often seen
  • Necrosis is common, both as single cell necrosis and larger foci
  • Often grows admixed with yolk sac tumor and can rarely form polyembryoma-like structures, called embryoid bodies
  • Residual seminiferous tubules may contain germ cell neoplasia in situ (GCNIS) or intratubular embryonal carcinoma, which entirely fills the tubule
  • Lymphovascular invasion is common within embryonal carcinoma predominant GCTs, is usually best visualized at the periphery testicle and may entirely occlude vessels, mimicking nodules of tumor
Microscopic (histologic) images

Contributed by Debra L. Zynger, M.D.

Solid growth

Glandular growth

Papillary growth

Cellular overlap


Admixed with yolk sac tumor


Lymphovascular invasion

Spermatic cord invasion

OCT 3/4





AE1 / AE3

Virtual slides

Images hosted on other servers:

Mixed GCT with predominance of embryonal carcinoma


Cytology description
  • No role in diagnosis of primary testicular GCT
Negative stains
Electron microscopy description
Molecular / cytogenetics description
Sample pathology report
  • Left testis, radical orchiectomy:
    • Mixed germ cell tumor, teratoma (45%), embryonal carcinoma (25%), yolk sac tumor (15%), seminoma (10%) and choriocarcinoma (5%) types (see synoptic report)
  • See staging information
Differential diagnosis
Board review style question #1

A 26 year old man presented with a left testicle mass. A radical orchiectomy was performed. Which is the correct diagnosis for the testicular germ cell tumor component shown in the above image?

  1. Choriocarcinoma
  2. Embryonal carcinoma
  3. Seminoma
  4. Teratoma
  5. Yolk sac tumor
Board review style answer #1
B. Embryonal carcinoma

Comment Here

Reference: Embryonal carcinoma
Board review style question #2

The H&E image above is a brain metastasis of testicular germ cell tumor with choriocarcinoma and embryonal carcinoma. Which of the following 2 immunostains will be positive in choriocarcinoma but weak or negative in embryonal carcinoma (one of which is shown above)?

  1. AFP, PLAP
  2. CD30, OCT 3/4
  3. CK7, p63
  4. D2-40, CD117
  5. SALL4, AE1 / AE3
Board review style answer #2
C. CK7, p63. CK7 (shown in the immunostain image above) is strongly and diffusely positive choriocarcinoma. CK7 is weak or negative in embryonal carcinoma. Expression for p63 is seen in mononucleated trophoblast cells in choriocarcinoma. p63 is negative in embryonal carcinoma. AFP is positive in yolk sac tumor and weak to negative in embryonal carcinoma and choriocarcinoma. PLAP is variably positive in embryonal carcinoma and negative in choriocarcinoma. CD30 and OCT 3/4 are positive in embryonal carcinoma and negative in choriocarcinoma. D2-40 and CD117 are positive in seminoma but negative in both choriocarcinoma and embryonal carcinoma. SALL4 and AE1 / AE3 are positive in both choriocarcinoma and embryonal carcinoma.

Comment Here

Reference: Embryonal carcinoma
Board review style question #3

In a testicular mixed germ cell tumor, increased percentage of which component correlates with a worse prognosis?

  1. Embryonal carcinoma
  2. Seminoma
  3. Spermatocytic tumor
  4. Teratoma
  5. Yolk sac tumor
Board review style answer #3
A. Embryonal carcinoma. In a testicular germ cell tumor, higher percentage of embryonal carcinoma and choriocarcinoma are associated with negative outcomes, such as local and distant metastases. Increased proportions of teratoma and yolk sac tumor are associated with better outcomes. In a mixed germ cell tumor, percentage of seminoma usually does not impact prognosis or management. Spermatocytic tumor is a germ cell tumor unrelated to germ cell neoplasia in situ.

Comment Here

Reference: Embryonal carcinoma
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